hoffman



W. M. HOFFMAN.

BORING MACHINE.

APPLICATION FILED OCT. 21. 1916.

l ,3 1 6,286. Patented Sept. 16, 1919.

2 SHEETS--SHEET 1.

k &

my W 741W W. M. HOFFMAN.

BORING MACHINE.

APPLICATION FILED OCT. 21, l9l6.

1 3 1 6,23 6 Patented Sept. 16, 1919.

2 SHEETS-SHEET 2.

" the article b which-is to bebored out as driven by any appropriatemeans,

, shells used for analogue 'By thus impinging WILLIAM H. HOFFMAN, 0FTORQNTO, ONTARIO, CANADA.

BORING MACHIN'E.

Specification of Letters Patent.

Patented Sept. 16, 1919.

Application and October 21, 1916. serial No. 126,838.

To all whom it may concern:

Be it known that I, WILLIAM M. Horr- MAN, citizen of the United States,residing at Toronto, county of York, Province of Ontarlo, Dominion ofCanada, have invented a certain new and useful Improve ment inBoring-Machines, and declare the.

following to be a full, scription of the same, such as will enableothers skilled in the art to which it pertains to make and use the same,reference being had to the accompanyin drawings, which form a part ofthis speci cation.

My invention relates to devices for borthe interior of explosive clear,and exact deing and truing up structures, and consists in the va-' riouscombinations hereinafter described and pointed out in the, claim.

In the drawings- Figure 1, is a detailed vertical sectional view of theupper p rtion of such a boring machine.

Fig. 2, is a lower portion of derstood that the detailed sectionalyiewof the my machine, it being unlower and upper portions fit together tomake one common machine,-

it being broken away at the point of join In the drawings, similar;letters refer to similar parts. a, represents a framework ofproportionate size and strength to hold hereinafter described. In theframework 0) is a socketva within whichthe article I) to be bored may beheld by set screws'c, c, or other convenient means. (1 is, a water pipeleading from any convenient source of water pp y the case shown is ashell having an orifice 0. upon the boring tool the water keeps-the tooland article to be bored comparatively cool. In the arrangement made italso has a further function, that is of'carrying the boring chipsdirectly awayfrom the surface upon which the boring is performed and outthrough the bottom of the shell in the direction shown at e',.

The framework ais of course adequately supported, but as the supportforms no part of the device it is not shown. In the lower part a, of theframeworka there is journaled a beveled gear wheel 7 driven by a pin.-ion f onthe shaft P which, in turn, is as a band military purposes, orother and which passes through the upper end of the article I) to bebored, which in liquid force pump;

introduction of water,

wheel f. Of wurse,-the shaft runs in appropriate bearing f* and isappropriately supported and driven in any convenient way and by anyconvenient means-which' meansis no part of m invention and which isfamiliar to every mechanic. On the hub of the'gear wheel is a ring 9somewhat la r er-in diameter t an the bearing 'and'held at t e hub ofthe wheel by set screw g. This ried a strong tube 'h. This tube It formsthe barrel of a hydraulic ram, the upper ring serves the purpose'ofkeeping the gearwheel in its bearing. Attached to the framework a, a anis a subframe a composed of 1 strong bars at the lower end of which iscarpurpose of saving weight.- At the upper end of the ramisa liange' 70'upon which is attached a ball bearing k This ram opcrates a pressure baror plunger .m having a spline n thereon which engages a correspondinggroove in the gearwheel .7 whereby the gearwheel compels upon thebearing 70 of the boring bar is arose-cutter p which, having cuttingsurfaces thereon andgroov'es there-for, trims out the other hollowmaterial to be operated upon,

' even to the foiward end thereof, with an;

suitable form that is chosen to be adopte It is obvious that the boringharm being slidably, but not rotatably attached to the gear wheel fmustrevolve with the gear wheel but may be pushed or fed into the interiorof the article to be operated upon by means of the hydraulic ram orplunger is. There is nothing new in the rinciple of operating this rain,which is y means of a therefore I. donot show it. Anoutlet k may whenthe tool is desired to descend, is opened and the tool descends by itsown, weight upon the outflow of the water at k". I y

.Oneof the chief. advantages of this form of boring bar is the fact thatheretofore in boring'bars and machines the boring bar has beenhorizontal and the chips would be in the way of the cutter. Inasmuch asmost of the material to be operated upon is of high carbon steel and thechips, when cut, become very hot, and when suddenly cooled by the areapt to be tempered more or less hard and thus not only the bar m torotate Upon the upper end endji of a shell or be furnished which,

interfere with the cutter but are apt to dig into the inner surface ofthe article to be operated upon and thus produce irregular? ties thereinas well as springin the bar over and making the interior sur aceeccentric with the exterior surface. By arranging the mechanism as Ihave described the device is very simple, very certain to work, and thechips are carried immediately away from the boring tool so that they donot 1nterfere with it.

I preferably use a form of cutter with a pilot nose 7' on which isadapted to enter the cored-out end into the perforation in the endthereof and although grooved for the purpose of the admission of water,yet acts as a pilot guide for the cutter to prevent any accidentalswerving of the cutter from the true line by reason of one side of thearticle being operated on being harder than the opposite side. Thispilot is shown at r. I

, prefer to mount the cutting tool upon the boring bar by a concentricscrewthread which is, of course, opposed to thedirection ing of the barupward, at the same timerotating it by means of the gears, enablestheinside of the rough article to be trimmed out and trued up with greatfacility and with the introduction of water, as stated, at the upperpart, the chips are all carried away without interfering with the work,so that the article. is certainly, expeditiously and accuratelyfinished.

I have not shown supports or holding means,ras those may be adapted tothe situation in which it is placed and inasmuch as they form no part ofmy invention I have not deemed it necessary to describe them.

Having thus described my invention, what I claim is" In a boringmachine, the combination of a vertical boring bar, a frame supportingthe same and adapted to support the article to be operated upon, a gearnon-rotatably but slidably mounted upon said boring bar and forming abearing therefor, a bearing in said frame for said gearwhe'el, means foroperating the gearwheel, a hydraulic ram for forcing the boring barvertically upward, and means for introducing water at the upper end ofthe article to be operated on, substantially as described.

In testimony whereof I sign this specification.

WILLIAM M. HOFFMAN.

